Cophixalus melanops, Kraus, Fred & Allison, Allen, 2009

Kraus, Fred & Allison, Allen, 2009, New species of Cophixalus (Anura: Microhylidae) from Papua New Guinea, Zootaxa 2128, pp. 1-38 : 15-19

Cophixalus melanops , sp. nov.

Figs. 2 A, B

Holotype. BPBM 20198 (field tag FK 9855), adult male, collected by F. Kraus on W slope Mt. Rio, 11.5081521ºS, 153.4308608ºE, 720–800 m, Sudest Island, Milne Bay Province, Papua New Guinea, 25 April 2004.

Paratypes (n = 9). BPBM 20192, W slope Mt. Rio, 11.5054347ºS, 153.429945ºE, 630–730 m, Sudest Island, 19 April 2004; BPBM 20193, W slope Mt. Rio, 11.49436ºS, 153.42542ºE, 440 m, Sudest Island, 21 April 2004; BPBM 20194, W slope Mt. Rio, 11.50402ºS, 153.42995ºE, 600 m, Sudest Island, 23 April 2004; BPBM 20195–96, same data as holotype except collected 23 April 2004; BPBM 20197, 20199, PNGNM 24066–67, same data as holotype.

Diagnosis. A small species (male SV = 16.4–18.9 mm, female SV = 21.8 mm) with finger discs smaller than toe discs (3rdF/4thT = 0.63–0.78); first finger of normal size, with disc bearing circum-marginal groove; wide head (HW/SV = 0.41–0.44); large eye (EY/SV = 0.14–0.17); small tympanum (TY/SV = 0.043–0.069), side of face uniformly black; lateral surfaces same color as dorsum or darker than dorsum but not bearing black lateral band; and short, black supratympanic bar.

Comparisons with other species. The new species differs from all Papuan congeners except C. misimae Richards and Oliver in the combination of having finger discs distinctly smaller than toe discs and a first finger of normal size, bearing a disc with a circum-marginal groove. Cophixalus melanops differs from C. misimae in having a wider head (HW/SV = 0.31–0.36 in C. misimae ), larger eye (EY/SV = 0.13–0.14 in C. misimae ), smaller tympanum (TY/SV = 0.065–0.075 in C. misimae ), lacking the black lateral band and inguinal black spots of the former, having the snout truncate in lateral view (projecting in C. misimae ), having oblique lores (vertical in C. misimae ), and having a black bar on the upper part of the tympanum (absent in C. misimae ).

Description of holotype. An adult male with right-lateral incision, vocal slits. Head moderately wide (HW/SV = 0.42), with steep but oblique loreal region; canthus rostralis rounded, straight when viewed from above; nostrils directed laterally, much closer to tip of snout than to eyes; internarial distance slightly larger than distance from naris to eye (EN/IN = 0.90, IN/SV = 0.111, EN/SV = 0.101); snout rounded and slightly projecting when viewed from the side, shallowly angulate when viewed from above; eyes large (EY/SV = 0.15); eyelid 2/3 width of interorbital distance; tympanum small (TY/SV = 0.058), with a clear, raised annulus. Dorsal and lateral surfaces smooth; supratympanic fold absent. Ventral surfaces generally smooth but weakly granular on abdomen. Fingers unwebbed, bearing discs with terminal grooves; relative lengths 3>4>2>1; first finger and disc well-developed. Finger discs approximately 1.5 times widths of penultimate phalanges, except for the first finger disc, which is only slightly wider than penultimate phalanx. Subarticular tubercles not obvious; metacarpal tubercles poorly developed, inner narrow and elongate, outer round. Toes unwebbed, bearing discs with terminal grooves; relative lengths 4>3>5>2>1. Toe discs larger than those of fingers (3rd F/4thT = 0.71); disc of fourth toe approximately twice width of penultimate phalanx; disc of first toe only slightly wider than penultimate phalanx. Subarticular tubercles reduced to mere skin thickenings; inner metatarsal tubercle narrow and elongate, outer lacking. Hind legs moderately long (TL/SV = 0.52).

Dorsum medium brown with few, scattered, tiny dark-brown spots and dark-brown postocular blotch; sides lighter. Face dark brown to angle of jaw, with few obscure ligher brown specks along mandible. Darkbrown stripe on lower half of anterior face of upper arm. Rear of thighs dorsally and proximally as for dorsum, ventrally and distally dark brown. Venter pale straw, heavily flecked with dark brown on chin and throat, sparsely flecked on chest and abdomen, producing high-contrasting appearance of light belly with dark chin and throat. Undersides of thighs light straw anteriorly, heavily flecked with dark brown posteriorly. Front of thighs pale straw with dark-brown flecks. Iris black, heavily flecked with silver-bronze.

Measurements (in mm). SV = 18.9, TL= 9.8, HW = 8.0, HL = 7.1, IN = 2.1, EN = 1.9, SN = 2.9, EY = 2.8, TY = 1.1, 3rd F = 0.64, 4th T = 0.90.

Variation. Mensural variation for the type series is shown in Table 8. The two adult paratypes have the snout more truncate than the holotype when seen in lateral view. The adult male paratype (BPBM 20192) is identical to the holotype in appearance. The adult female paratype (BPBM 20197) has dark-brown dorsolateral stripes extending on each side from scapular region to groin; sides below this stripe darker than dorsum; chest more heavily flecked with dark brown than in holotype. The remaining paratypes are all juveniles and are similar in appearance to the holotype except that there are variable amounts of dark-brown flecking on the chest.

Color in life. BPBM 20192: “Dorsum uniform red-brown. Short black postocular stripe followed by a black dot. Face black. Narrow light-brown line on canthus and rim of upper eyelid. Iris dark copper. Chin and throat pale straw mottled with dark gray. Chest and belly uniform straw with minute white punctations. Under thighs straw, mottled distally with dark gray. Rear of thighs same.” BPBM 20197 was described as: “Dorsum rich orange-brown with very narrow tan vertebral stripe and narrow black dosolateral stripes. Sides straw, heavily dusted with gray and with few black spots. Side of face black. Iris orange-brown. Chin, throat, and chest light gray mostly covered by dense charcoal-gray flecking. Belly and under thighs dull yellow with some dark gray flecks, especially toward rear of thighs. Rear of thighs orange-brown heavily covered with charcoal-gray flecks.”

Call. Call not heard by us.

Etymology. The name is a single-ending latinized Greek compound adjective combining “melanus”, meaning “black”, and “ops”, meaning “face”.

Range. Known only from Sudest Island, Milne Bay Province, Papua New Guinea ( Fig. 4 ).

Ecological notes. Animals were found active on the forest floor during the day in primary lowland rainforest along ridgelines from 440–800 m elevation. The upper 200 m of this distribution consists of lowstature, dense cloud forest, and represents the highest reaches of the island. The general area of collection was described by Brass (1959: 52–53).

Figures

FIGURE 2. Photos in life of (A) holotype of Cophixalus melanops (BPBM 20198), (B) paratype of Cophixalus melanops (BPBM 20197), (C) holotype of Cophixalus linnaeus (BPBM 31836), (D) paratype of Cophixalus phaeobalius (BPBM 26194), (E) paratype of Cophixalus tomaiodactylus (BPBM 26182), and (F) holotype of Cophixalus tomaiodactylus (BPBM 26185).

FIGURE 4. Map showing known distributions for Cophixalus cupricarenus (inverted triangles), C. desticans (circles), C. iovaorum (triangle), C. melanops (star), and C. tomaiodactylus (squares). Filled symbols are type localities; open symbols are additional localities, as relevant.